Study Finds Less Toxic Treatment for Myeloma

THURSDAY, Oct. 22 -- Cancer researchers say they have a better treatment for patients with newly diagnosed multiple myeloma than the current standard therapy.

Their study finds that treatment with lenalidomide plus low-dose dexamethasone is associated with better short-term survival and with lower toxicity than lenalidomide plus high-dose dexamethasone, which is the mainstay of therapy for the bone marrow cancer.

The study included more than 400 patients with untreated, symptomatic myeloma who received lenalidomide (25 milligrams for 21 days) plus a high dose of dexamethasone (40 milligrams on days one to four, nine to 12, and 17 to 20 of a 28-day cycle), or who received lenalidomide on the same schedule with a low dose of dexamethasone (40 milligrams on days one, eight, 15 and 22 of a 28-day cycle).

Within four cycles, 79 percent of patients in the high-dose group and 68 percent of patients in the low-dose group had complete or partial response, the researchers found. After one year, overall survival was 96 percent in the low-dose group and 87 percent in the high-dose group. These findings led the researchers to stop the trial and switch patients in the high-dose group to low-dose therapy.

During the first four months of the study, 52 percent of patients in the high-dose group and 35 percent of those in the low-dose group had grade 3 or worse toxic effects. These included deep-vein thrombosis, fatigue and infections, including pneumonia.

Also during the first four months of the trial, 5 percent of patients in the high-dose group died, compared with less than 1 percent of those in the low-dose group, the study authors reported.

"High-dose dexamethasone in a community setting seems more toxic than low-dose dexamethasone, with more early deaths in the first four months, increased risk of thromboembolic complications, and higher overall risk of serious adverse events, particularly in patients older than 65 years," wrote Dr. S. Vincent Rajkumar, of the Mayo Clinic, and colleagues.

The authors concluded that the trial "shows that low-dose dexamethasone in conjunction with lenalidomide is an active regimen for newly diagnosed myeloma with acceptable toxicity and low early mortality."

They also noted that "the use of high-dose dexamethasone is not needed for the most part in the context of new active agents for myeloma, and as a result almost all current phase 3 trials have adopted low-dose dexamethasone as the standard in combination regimens."